Most damage I've witnessed is in mostly residential panels. Specs usually 250in lbs on mains, that is not much at all, seen guys not using a torque wrench thinking that you wrench tighten. Most times if torque it out, ends up in neighborhood of 60 ft lbs. 3X the recommended torque. No gorilla needed to do that.
That's interesting. Most times I check torque on those kinds of connections I find them loose. And I have a habit of torquing 250in-lb. connections to a bit less than spec because too often something breaks if I torque it to spec.
Maybe. I am skeptical how much scientific analysis goes into torque values. I think it's more just based on the size of the set screw in the lug. Considering the typical wide range of conductor sizes, different conductor materials, and stranding types that can go in a typical lug, I am skeptical the published torque values are meaningfull.
Yeah, it would stand to reason that the published value is assumed to fall within the overlapping ranges of acceptability for all those different factors you mention. Which means for any given conductor choice, the risk of overtorquing vs. undertorquing could be different.
FWIW there are many sizes of Polaris blocks; some of them can take 500KCMIL conductors.
I don't think anyone has said that the levels of risk are the same.
I was just thinking about this, reading through. If you damaged the strands during initial stripping, and then over-torqued the block, I imagine you could sever strands pretty easily, leading to increased resistance, heat, etc. We've seen a number of these melt; polaris, burndy, panduit, doesn't matter. I have searched the internet for hours trying to find recalls, examples of bad batches, etc. I'm convinced it's installation error 100% of the time. Having a properly calibrated torque screwdriver/wrench is critical.
